Panties and briefs have been made by cutting diametrically opposed leg openings in one end of a tubular blank formed by a circular knitting machine and joining the ends of the blank that are between the leg openings. Since the material in the leg openings is about one 20% of all the material used in a panty or brief, there is considerable waste.
This method of manufacture is described in U.S. Pat. No. 4,624,115 ('115), wherein a tubular blank is formed by a circular knitting machine with areas on opposite sides having a stitch that differs in appearance from the rest of the blank so as to form a line of demarcation that can serve as a cutting guide. The ends of the tubular blank between these areas are sewn together to form a crotch piece and leg openings.
U.S. Pat. No. 4,093,156 ('156) proposed that shaped panels appending from the front and rear of a tubular body be formed by a circular knitting machine and that the ends of the panels be overlapped and sewn together so as to form a member that extends through the crotch. Each panel is widest where it joins the tubular body and gradually reduces in width until it meets an end portion of constant width. Whereas this saves material, high speed production is difficult to obtain. Furthermore, because of the tendency for the edges of the leg openings thus formed to ripple and pucker, it is difficult to trim them with elastic material or the like so as to cover the floats or ends of yarn that are necessarily present at the edges of the panels.